USGS - science for a changing world

USGS Geoscience Data Catalog

Geology and resource assessment of the Venezuelan Guayana Shield at 1:500,000 scale

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:


What does this data set describe?

Title:
Geology and resource assessment of the Venezuelan Guayana Shield at 1:500,000 scale
Abstract:
The data in this CD-ROM are based on a mineral resource assessment of the Venezuelan Guayana Shield, conducted between 1987 and 1991 by the U.S. Geological Survey and Corporaci—n Venezolana de Guayana, TŽcnica Minera, (USGS, 1993). The Venezuelan Shield occupies about 415,000 sq km in the south and east part of Venezuela. The study area is bounded on the north by the R’o Orinoco. It includes all of the Territorio Federal Amazonas, Estado Bol’var, and part of Estado Delta Amacuro. The original resource assessment publication USGS Bulletin 2062 consists of 121 pages of text and figures as well as eight full-color maps:
Geographic Geologic and tectonic Bouguer gravity Two mineral-occurrence maps Side-looking airborne radar image Two permissive domain maps
The side-looking airborne radar image and the Bouguer gravity map are not included in this CD-ROM. The geology layer from the 1993 Bulletin was revised and published as a series of MF and I maps
  1. How might this data set be cited?
    Schruben, Paul G., Wynn, Jeffrey C., Gray, Floyd, Cox, Dennis P., Stewart, John H., and Brooks, William E., 1997, Geology and resource assessment of the Venezuelan Guayana Shield at 1:500,000 scale: U.S. Geological Survey Digital Data Series 46.

    Online Links:

    Other_Citation_Details:
    ARC/INFO coverages and ARCVIEW project (31MB). ARC/INFO export files (28MB).
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -75.0
    East_Bounding_Coordinate: -57.0
    North_Bounding_Coordinate: 13.0
    South_Bounding_Coordinate: 0.0
  3. What does it look like?
    http://pubs.usgs.gov/dds/dds46/geology.gif (GIF)
    Geology of the Venezuelan Guyana Shield at 1:500000 Scale
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 1993Currentness_Reference:
    Publication date of the original series of maps found in USGS 1993 Bulletin 2062 and the CD-ROM (1997)
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: map
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a vector data set. It contains the following vector data types (SDTS terminology):
      • Point
      • Complete chain
      • GT-polygon composed of chains
    2. What coordinate system is used to represent geographic features?
      The map projection used is Albers Conical Equal Area.
      Projection parameters:
      Standard_Parallel: 9.0
      Standard_Parallel: 4.0
      Longitude_of_Central_Meridian: -66.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 0.0
      False_Northing: 0.0
  7. How does the data set describe geographic features?
    VZGE.PAT
    Venezuelan Guyana Shield geologic map units (Source: DDS-46)
    Lc
    mixed-case rock-unit code (Source: B-2062)
    ValueDefinition
    blankUnmapped area
    dDiabase - mafic dikes undivided (Mesozoic to M Proterozoic)
    dioritFenitized diorite & tonalie at Cerro Impacto
    icCarbonatite(?) intrusion of Cerro Impacto
    QalAlluvial deposits of sand, gravel, and silt (Quaternary)
    QTmMesa Fm. siltstone and sandy siltstone (Pleistocene & Plio)
    waterarea of water
    XaAmphibolite schist containing andesine (E Prot)
    XAgrGranitic rx of Imataca Complex (E Prot and/or Archean)
    XAiImataca Complex orthogneiss and paragneiss (Archean)
    XAmMigmatite & gneiss of Imataca Complex (E Prot or Archean)
    XbcBasement complex granite to granodiorite gneiss (E Prot)
    XcbCaballape Fm felsic metatuff and phyllite (E Prot)
    XccCicapra Fm (Carichapo Gp) mafic to intermed metatuff E Prot
    XceEl Callao Fm (Carichapo Gp) greenstone, greenschist (E Prot
    XcgGranitic rocks of Cuchivero Group (Early Proterozoic)
    XcoCinaruco Fm qtzite, sericitic qtzite, schist (E Prot)
    XcvCaicara Fm (Cuchivero Gp) rhyodacitic-rhyolitic tuff E Prot
    Xf1Felsic metatuff and flows (Early Proterozoic)
    Xf2Felsic metatuff and flows, eugeosynclinal terrane (E Prot)
    XgCalc-alkaline granite & other silicic plutonic rx (E Prot)
    Xg1Metagabbro (greenstone belts) (Early Proterozoic)
    Xg2Metagabbro (eugeosynclinal terrane) (Early Proterozoic)
    XgrGranitic rocks, mostly quartz monzonite (Early Proterozoic)
    XguGranitic silicic to intermediate intrusive rocks (E Prot)
    XlcLos Caribes Fm arkose, polymict congl, phyllite (E Prot)
    Xm1Meta-mafic to intermediate flow and pyroclastic rx (E Prot)
    Xm2Mafic to intermediate metalava and metatuff (E Proterozoic
    XmaMaracapra Fm red beds, felsic volcanics (E Proterozoic)
    XmoMoriche Fm metasedimentary conglomerates (E Prot)
    XmpIntrusive rx of San Carlos metamorphic-plut terrane (E Prot
    XmuGreenstone belt rocks, undivided (Early Proterozoic)
    XprPre-Roraima Gp sedimentary rx clay-rich sandstone (E Prot)
    Xs1Schist, phyllite, metatuffs, and metavolcanic rx (E Prot)
    Xs2Muscovite schist and phyllite, eugeosynclinal terr (E Prot)
    XsmSeds and metaseds of uncertain affinity qtz arenite (E Prot
    XspSupamo Complex sodic granitic rx, paragneiss, etc. (E Prot)
    Xu1Metaperidotite, metapyroxenite, serp & talc schist (E Prot)
    Xu2Ultramafic rx metaperidotite, metapyroxenite, etc. (E Prot)
    XuiUltramafic intrusive rx in La Flor-Carapo area (E Prot)
    XyfYuruari Fm (Pastora Sg) felsic metatuff (E Prot)
    XysYuruari Fm Pastora Sg qtz muscovite schist, phyllite E Prot
    YlgLate granite intrusive in, and doming Roraima seds (M Prot)
    YpParguaza granite, massive, porphryitic & biotite (M Prot)
    YXacAlkaline intrusive complexes (Middle to Early Proterozoic)
    YXacAlkaline intrusive complexes (Middle to Early Proterozoic)
    YXrRoraima Group (undivided) qtz arenite, arkose M &/or E Prot
    YXraAuyantepuy Fm (Roraima Gp) quartz arenite, arkose M, E Prot
    YXrcCanaima Fm (Roraima Gp) qtz arenite, arkose, etc. M, E Prot
    YXrgGuaiquinima Fm (Roraima Gp) qtz arenite, arkose M, E Prot
    FMATN
    Upper-case rock unit code (Source: DDS-46)
    PTYPEI
    PTYPEI is a two-digit integer that is used to sort the units into groups of related rocks. The PTYPEI integer is not distict for every rock type but changes for different quadrangles. (Source: DDS-46)
    DESC
    Short description of rock unit. (Source: DDS-46)
    PTYPES & PTYPER
    PTYPES is composed of PTYPEI, Lc, and DESC. (Source: DDS-46)
    VZGE.AAT
    Geologic and other contacts (Source: DDS-46)
    DESC
    Short description of contact type (Source: DDS-46)
    FTYPEI
    assigned number for each contact type (Source: DDS-46)
    ValueDefinition
    18surface water body
    23geological contact hidden
    21geological contact
    16international boundary
    FTYPES
    composed of FTYPEI and DESC (Source: DDS-46)
    VZFT.AAT
    mapped faults (Source: DDS-46)
    FTYPEI
    assigned number for each fault type (Source: DDS-46)
    ValueDefinition
    1fault
    2fault - inferred (dashed)
    3fault - implied (dotted)
    4thrust fault
    4sag fault
    6fold axis
    7graben
    8graben - hidden
    9shear zone
    10U or Th anomaly
    11structural trend
    12ring structure
    13iron formations
    14major magnetic gradient
    15fault movement and fold arrows
    DESC
    Short description of fault (Source: DDS-46)
    FTYPES
    composed of FTYPEI and DESC (Source: DDS-46)
    RA.PAT
    Resources in TRACT MAP A (Source: DDS-46)
    TRACT
    symbol contains roman numeral and lower-case letter and distinguishes between mineral deposits (Source: DDS-46)
    ValueDefinition
    IaAlgoma iron and sedimentary manganese deposits, permissive
    IbAlgoma iron and sedimentary manganese deposits, low probability
    IIaLow-sulfide gold-quartz vein deposits, permissive
    IIbLow-sulfide gold-quartz vein deposits, low probability
    VITin greisen deposits
    VIIIPorphyry copper and volcanic-hosted magnetite deposits
    FMATN
    symbol contains number and upper-case letter and distinguishes between mineral deposits (Source: DDS-46)
    DESC
    Short description of type of mineral deposit (Source: DDS-46)
    KEY
    composed of TRACT and DESC (Source: DDS-46)
    RB.PAT
    Resources in TRACT MAP B (Source: DDS-46)
    TRACT
    symbol contains roman numeral and distinguishes between mineral deposits (Source: DDS-46)
    ValueDefinition
    IIIKuroko-type massive sulfide deposits
    IVSynorogenic-synvolcanic Ni-Cu & related platinum deposits
    VCarbonatite deposits and diamond-bearing kimberlite pipes
    VIISedimentary kaolin deposits
    FMATN
    symbol contains roman numeral and distinguishes between mineral deposits (Source: DDS-46)
    DESC
    short description of mineral deposit type (Source: DDS-46)
    KEY
    composed of TRACT and DESC (Source: DDS-46)
    DEPOSIT
    mineral deposits, prospects, and occurrences (Source: DDS-46)
    Site
    deposit site name (Source: DDS-46)
    City_code
    two letter code for country where deposit is located (Source: DDS-46)
    ValueDefinition
    BRBrazil
    GYGuyana
    NSSurinam
    VEVenezuela
    FGFrench Guyana
    STATE
    distinct area of the country where the deposit is located (Source: DDS-46)
    LATITUDE
    Latitude of deposit (Source: DDS-46)
    LONGITUDE
    Longitude of deposit (Source: DDS-46)
    COMMOD_GP
    main commercial deposit (Source: DDS-46)
    COMMOD
    list of abbreviated commercial deposits (Source: DDS-46)
    COMMODL
    abbreviated main commercial deposit (Source: DDS-46)
    ORE.MAT
    ore material (Source: DDS-46)
    DEP.TYPE
    type of deposit (Source: DDS-46)
    DEP.COMMENTS
    comments on the deposit type (Source: DDS-46)
    MODEL
    Model of the deposit type (Source: DDS-46)
    HOST.RK.NAME
    Name of host rock (Source: DDS-46)
    HOST.RK.TYPE
    Type of host rock (Source: DDS-46)
    HOST.RK.AGE
    Age of host rock (Source: DDS-46)
    ASSOC.RK.NAME
    Name of associated rock (Source: DDS-46)
    ASSOC.RK.TYPE
    Type of associated rock (Source: DDS-46)
    ASSOC.RK.AGE
    Age of associated rock (Source: DDS-46)
    ALTERATION
    alteration of surrounding rocks (Source: DDS-46)
    GEOL.COMMENTS
    Comments on the geology (Source: DDS-46)
    GEN.COMMENTS
    General comments (Source: DDS-46)
    REFERENCE
    Citation of reference work (Source: DDS-46)
    VZMA.PAT
    Buried magnetic bodies in Venezuela. (Source: DDS-46)
    DEPTH
    Depth to magnetic body (Source: DDS-46)
    ValueDefinition
    sshallow depth
    Range of values
    Minimum:1
    Maximum:10
    CROSS
    characteristics of magnetic body
    ValueDefinition
    POSPositive magnetic anomoly
    NEGNegative magnetic anomoly
    DEEPDeep magnetic anomoly
    BLANKno comment
    Entity_and_Attribute_Overview:
    These files are compatible with ArcView 1 and ARC/INFO Version 6.1.2 or later. The files are contained in 11 directories. Ten of those directories contain coverages for the individual quadrangle publications. The eleventh directory, "vz", contains the same information but in the form of a combined map with all the quadrangles tiled together into a single coverage.
    The coverages for the individual quadrangles have the same features as the combined coverage. The only differences are in some of the file names. For instance, the place names and city points in the individual quadrangles are stored in files called "*anno5.e00" as opposed to "places.e00" for the combined coverage.
    ArcView views and themes                                coverage name
    -------------------------------------------------------------------
    
    Venezuelan Guayana Shield, all quadrangles              vz.av
    
    Venezuela national boundary                             vzctry
    Venezuela province boundary                             vzprov
    Scale bar annotation                                    scale
    Scale bar                                               scale
    Place names                                             places
    Place points                                            places
    Roads                                                   vzrd
    Outer quad outline                                      vzout
    Outer quad outline, lat/long numbers                    vzout
    Latitude/longitude tics                                 vztc
    Index map annotation                                    index
    Index map lat/long grid only                            grid
    Index map, colored countries, lat/long grid             index
    Streams annotation                                      vzst
    Streams                                                 vzst
    Mineral deposits                                        deposit
    Linear features annotation                              vzft
    Linear features                                         vzft
    A. Permissive domains annotation                        raanno
    A. Permissive domains leaders                           raanno
    A. Permissive domains for selected Fe, Au, Sn,          ra
    Cu deposits
    A. Permissive domains poly arcs only                    ra
    B. Permissive domains structure annotation              rbstruct
    B. Permissive domains structure lines                   rbstruct
    B. Permissive domains annotation                        rbanno
    B. Permissive domains leaders                           rbanno
    B. Permissive domains for selected Pb-Zn, Ni-Cu,        rb
    diamond, kaolin deposits
    B. Permissive domains poly arcs only                    rb
    Correlation of map units annotation                     vzcor
    Correlation of map units polygons                       vzcor
    Buried magnetic bodies                                  vzma
    Rock unit labels                                        vzlab
    Rock unit labels leaders                                vzlab
    Geology arcs                                            vzge
    Geology polygons                                        vzge
    
    
    Guri and southern part of the Tucupita 2øx3ø            gu.av
    quadrangles
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    Guri, quadrangle lat/long tics                          gutc
    Guri, quadrangle lat/long numbers                       guout
    Guri, quadrangle outline                                guout
    Guri, place name annotation                             guanno5
    Guri, city points                                       guanno5
    Guri, roads                                             gurd
    Guri, province boundary                                 gupl
    Guri, streams annotation                                gust
    Guri, streams                                           gust
    Guri, linear feature annotation                         guft
    Guri, linear features                                   guft
    Guri, correlation of map units annotation               gucor
    Guri, correlation of map units polygons                 gucor
    Guri, map key annotation                                guleg
    Guri, map key points                                    gulegpt
    Guri, map key arcs                                      guleg
    Guri, map key polygons                                  guleg
    Guri, scale bar annotation                              guscale
    Guri, scale bar                                         guscale
    Guri, rock unit labels                                  gulab
    Guri, rock unit labels leaders                          gulab
    Guri, geology arcs                                      guge
    Guri, geology polygons                                  guge
    
    
    Ciudad Piar and part of the Ciudad Bolivar 2øx3ø        pi.av
    quadrangles
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    Ciudad Piar, quadrangle lat/long tics                   pitc
    Ciudad Piar, quadrangle lat/long numbers                piout
    Ciudad Piar, quadrangle outline                         piout
    Ciudad Piar, place name annotation                      pianno5
    Ciudad Piar, city points                                pianno5
    Ciudad Piar, roads                                      pird
    Ciudad Piar, province boundary                          pipl
    Ciudad Piar, streams annotation                         pist
    Ciudad Piar, streams                                    pist
    Ciudad Piar, linear feature annotation                  pift
    Ciudad Piar, linear features                            pift
    Ciudad Piar, structural trends from SLAR                pisr
    Ciudad Piar, correlation of map units annotation        picor
    Ciudad Piar, correlation of map units polygons          picor
    Ciudad Piar, map key annotation                         pileg
    Ciudad Piar, map key points                             pilegpt
    Ciudad Piar, map key arcs                               pileg
    Ciudad Piar, map key polygons                           pileg
    Ciudad Piar, scale bar annotation                       piscale
    Ciudad Piar, scale bar                                  piscale
    Ciudad Piar, rock unit labels                           pilab
    Ciudad Piar, rock unit labels leaders                   pilab
    Ciudad Piar, kimberlite area annotation                 pima
    Ciudad Piar, kimberlite area                            pima
    Ciudad Piar, geology arcs                               pige
    Ciudad Piar, geology polygons                           pige
    
    
    San Fernando de Apure 2øx3ø quadrangle (Bolivar part)   sf.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    San Fernando, quadrangle lat/long tics                  sftc
    San Fernando, quadrangle lat/long numbers               sfout
    San Fernando, quadrangle outline                        sfout
    San Fernando, place name annotation                     sfanno5
    San Fernando, city points                               sfanno5
    San Fernando, province boundary                         sfpl
    San Fernando, streams annotation                        sfst
    San Fernando, streams                                   sfst
    San Fernando, linear features                           sfft
    San Fernando, correlation of map units annotation       sfcor
    San Fernando, correlation of map units polygons         sfcor
    San Fernando, map key annotation                        sfleg
    San Fernando, map key points                            sflegpt
    San Fernando, map key arcs                              sfleg
    San Fernando, map key polygons                          sfleg
    San Fernando, scale bar annotation                      sfscale
    San Fernando, scale bar                                 sfscale
    San Fernando, rock unit labels                          sflab
    San Fernando, rock unit label leaders                   sflab
    San Fernando, geology arcs                              sfge
    San Fernando, geology polygons                          sfge
    
    
    Santa Elena 2øx3ø quadrangle (Venezuela part)           se.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    Santa Elena, quadrangle lat/long tics                   setc
    Santa Elena, quadrangle lat/long numbers                seout
    Santa Elena, quadrangle outline                         seout
    Santa Elena, place name annotation                      seanno5
    Santa Elena, city points                                seanno5
    Santa Elena, roads                                      serd
    Santa Elena, province boundary                          sepl
    Santa Elena, stream annotation                          sest
    Santa Elena, streams                                    sest
    Santa Elena, linear feature annotation                  seft
    Santa Elena, linear features                            seft
    Santa Elena, correlation of map units annotation        secor
    Santa Elena, correlation of map units polygons          secor
    Santa Elena, map key annotation                         seleg
    Santa Elena, map key points                             selegpt
    Santa Elena, map key arcs                               seleg
    Santa Elena, map key polygons                           seleg
    Santa Elena, scale bar annotation                       sescale
    Santa Elena, scale bar                                  sescale
    Santa Elena, rock unit labels                           selab
    Santa Elena, rock unit labels leaders                   selab
    Santa Elena, geology arcs                               sege
    Santa Elena, geology polygons                           sege
    
    
    R¡o Caura 2ø by 3ø quadrangle                           ca.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    R¡o Caura, quadrangle lat/long tics                     catc
    R¡o Caura, quadrangle lat/long numbers                  caout
    R¡o Caura, quadrangle outline                           caout
    R¡o Caura, place name annotation                        caanno5
    R¡o Caura, city points                                  caanno5
    R¡o Caura, province boundary                            capl
    R¡o Caura, stream annotation                            cast
    R¡o Caura, streams                                      cast
    R¡o Caura, linear features annotation                   caft
    R¡o Caura, linear features                              caft
    R¡o Caura, correlation of map units annotation          cacor
    R¡o Caura, correlation of map units polygons            cacor
    R¡o Caura, map key annotation                           caleg
    R¡o Caura, map key points                               calegpt
    R¡o Caura, map key arcs                                 caleg
    R¡o Caura, map key magnetics                            caleg
    R¡o Caura, map key polygons                             caleg
    R¡o Caura, scale bar annotation                         cascale
    R¡o Caura, scale bar                                    cascale
    R¡o Caura, rock unit labels                             calab
    R¡o Caura, rock unit labels leaders                     calab
    R¡o Caura, buried magnetic bodies                       cama
    R¡o Caura, geology arcs                                 cage
    R¡o Caura, geology polygons                             cage
    
    
    Puerto Ayacucho 2øx3ø quadrangle (Venezuela part)       ay.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    Puerto Ayacucho, quadrangle lat/long tics               aytc
    Puerto Ayacucho, quadrangle lat/long numbers            ayout
    Puerto Ayacucho, quadrangle outline                     ayout
    Puerto Ayacucho, place name annotation                  ayanno5
    Puerto Ayacucho, city points                            ayanno5
    Puerto Ayacucho, roads                                  ayrd
    Puerto Ayacucho, province boundary                      aypl
    Puerto Ayacucho, streams annotation                     ayst
    Puerto Ayacucho, streams                                ayst
    Puerto Ayacucho, linear features                        ayft
    Puerto Ayacucho, correlation of map units annotation    aycor
    Puerto Ayacucho, correlation of map units polygons      aycor
    Puerto Ayacucho, map key annotation                     ayleg
    Puerto Ayacucho, map key points                         aylegpt
    Puerto Ayacucho, map key arcs                           ayleg
    Puerto Ayacucho, map key magnetics                      ayleg
    Puerto Ayacucho, map key polygons                       ayleg
    Puerto Ayacucho, scale bar annotation                   ayscale
    Puerto Ayacucho, scale bar                              ayscale
    Puerto Ayacucho, rock unit labels                       aylab
    Puerto Ayacucho, rock unit labels leaders               aylab
    Puerto Ayacucho, section line annotation                aylabcr
    Puerto Ayacucho, section line on map                    aylabcr
    Puerto Ayacucho, section annotation                     aycrm
    Puerto Ayacucho, section leaders                        aycrm
    Puerto Ayacucho, section geology arcs                   aycrm
    Puerto Ayacucho, section geology polygons               aycrm
    Puerto Ayacucho, buried mag annotation                  aymalab
    Puerto Ayacucho, buried mag leaders                     aymalab
    Puerto Ayacucho, buried magnetic bodies                 ayma
    Puerto Ayacucho, geology arcs                           ayge
    Puerto Ayacucho, geology polygons                       ayge
    
    
    La Esmeralda 2øx3ø quadrangle (Venezuela part)          es.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    La Esmeralda, quadrangle lat/long numbers               esout
    La Esmeralda, quadrangle outline                        esout
    La Esmeralda, place name annotation                     esanno5
    La Esmeralda, city points                               esanno5
    La Esmeralda, province boundary                         espl
    La Esmeralda, streams annotation                        esst
    La Esmeralda, streams                                   esst
    La Esmeralda, linear features                           esft
    La Esmeralda, structural trends from SLAR               essr
    La Esmeralda, correlation of map units annotation       escor
    La Esmeralda, correlation of map units polygons         escor
    La Esmeralda, map key annotation                        esleg
    La Esmeralda, map key points                            eslegpt
    La Esmeralda, map key arcs                              esleg
    La Esmeralda, map key polygons                          esleg
    La Esmeralda, rock unit labels                          eslab
    La Esmeralda, rock unit labels leaders                  eslab
    La Esmeralda, buried magnetic bodies                    esma
    La Esmeralda, geology arcs                              esge
    La Esmeralda, geology polygons                          esge
    
    
    Atabapo 2øx3ø quadrangle (Venezuela part)               at.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    Atabapo, quadrangle lat/long numbers                    atout
    Atabapo, quadrangle outline                             atout
    Atabapo, place name annotation                          atanno5
    Atabapo, swamp symbols                                  atanno5
    Atabapo, province boundary                              atpl
    Atabapo, streams annotation                             atst
    Atabapo, streams                                        atst
    Atabapo, linear features                                atft
    Atabapo, correlation of map units annotation            atcor
    Atabapo, correlation of map units polygons              atcor
    Atabapo, map key annotation                             atleg
    Atabapo, map key arcs                                   atleg
    Atabapo, map key magnetics                              atleg
    Atabapo, map key polygons                               atleg
    Atabapo, scale bar annotation                           atscale
    Atabapo, scale bar                                      atscale
    Atabapo, rock unit labels                               atlab
    Atabapo, rock unit labels leaders                       atlab
    Atabapo, buried magnetic bodies                         atma
    Atabapo, geology arcs                                   atge
    Atabapo, geology polygons                               atge
    
    
    R¡o Mavaca 2øx3ø quadrangle (Venezuela part)            ma.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    R¡o Mavaca, quadrangle lat/long numbers                 maout
    R¡o Mavaca, quadrangle outline                          maout
    R¡o Mavaca, place name annotation                       maanno5
    R¡o Mavaca, city points                                 maanno5
    R¡o Mavaca, streams annotation                          mast
    R¡o Mavaca, streams                                     mast
    R¡o Mavaca, linear features                             maft
    R¡o Mavaca, correlation of map units annotation         macor
    R¡o Mavaca, correlation of map units polygons           macor
    R¡o Mavaca, map key annotation                          maleg
    R¡o Mavaca, map key arcs                                maleg
    R¡o Mavaca, map key magnetics                           maleg
    R¡o Mavaca, map key polygons                            maleg
    R¡o Mavaca, scale bar annotation                        mascale
    R¡o Mavaca, scale bar                                   mascale
    R¡o Mavaca, rock unit labels                            malab
    R¡o Mavaca, rock unit labels leaders                    malab
    R¡o Mavaca, geology arcs                                mage
    R¡o Mavaca, buried magnetic bodies                      mama
    R¡o Mavaca, geology polygons                            mage
    
    
    Piedra de Cocuy 2øx3ø quadrangle (Venezuela part)       pc.av
    
    Index map, latitude/longitude tics                      vztc
    Index map, annotation                                   index
    Index map, lat/long grid only                           grid
    Index map, colored countries, lat/long grid             index
    Piedra de Cocuy, quadrangle lat/long numbers            pcout
    Piedra de Cocuy, quadrangle outline                     pcout
    Piedra de Cocuy, place name annotation                  pcanno5
    Piedra de Cocuy, city points                            pcanno5
    Piedra de Cocuy, province boundary                      pcpl
    Piedra de Cocuy, streams annotation                     pcst
    Piedra de Cocuy, streams                                pcst
    Piedra de Cocuy, linear features                        pcft
    Piedra de Cocuy, structural trends from SLAR            pcsr
    Piedra de Cocuy, correlation of map units annotation    pccor
    Piedra de Cocuy, correlation of map units polygons      pccor
    Piedra de Cocuy, map key annotation                     pcleg
    Piedra de Cocuy, map key points                         pclegpt
    Piedra de Cocuy, map key arcs                           pcleg
    Piedra de Cocuy, map key magnetics                      pcleg
    Piedra de Cocuy, map key polygons                       pcleg
    Piedra de Cocuy, scale bar annotation                   pcscale
    Piedra de Cocuy, scale bar                              pcscale
    Piedra de Cocuy, rock unit labels                       pclab
    Piedra de Cocuy, rock unit labels leaders               pclab
    Piedra de Cocuy, geology arcs                           pcge
    Piedra de Cocuy, buried magnetic bodies                 pcma
    Piedra de Cocuy, geology polygons                       pcge
    
    Entity_and_Attribute_Detail_Citation:
    More detailed information can be found on the online help file from http://pubs.usgs.gov/dds/dds46/ and the U.S. Geological Survey Bulletin 2062.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Schruben, Paul G.
    Minerals Information Office
    Mail Stop 920, National Center
    U.S. Geological Survey
    12201 Sunrise Valley Drive
    Reston, VA
    USA

    (703) 648-6142 (voice)
    (703) 648-6057 (FAX)
    pschruben@usgs.gov

Why was the data set created?

Conversion of the Venezuela maps to a computerized digital format was undertaken for the following reasons:
1) The digital format facilitates the presentation and analysis of earth-science data. Digital maps can be displayed at any scale or projection, whereas a paper map has a fixed scale and projection. However, the maps on this disc are not intended to be used at any scale more detailed than 1:500,000.
A geographic information system (GIS) allows combining and overlaying of layers for analysis of spatial relations not readily apparent in the standard paper publication. Digital data on geology, geophysics, and geochemistry can be combined to create useful derivative products.
2) The digital format was used to facilitate publication in both paper and electronic form. For the R’o Caura paper map publication (Brooks and others, 1995), digital images were sent to the Gerber plotter, a vector-to-film processor. The other 1:500,000-scale MF maps were reproduced photographically from electrostatic plotter output on clear mylar. The published digital formats include this CD-ROM and ARC/INFO Export files to be located on the World Wide Web on the Internet.

How was the data set created?

  1. From what previous works were the data drawn?
    Brunstein et al. (1993) (source 1 of 1)
    Brunstein, Frederick C., Emery, David A., Stettner, Will, and Stoeser, Judith W., 1993, Geology and mineral resource assessment of the Venezuelan Guayana Shield: U.S. Geological Survey Bulletin B-2062, U.S. Geological Survey, Denver, Colorado.

    Type_of_Source_Media: Paper
    Source_Scale_Denominator: 500000
    Source_Contribution:
    The geologic map and mineral deposit maps were scanned from Bulletin 2062.
  2. How were the data generated, processed, and modified?
    (process 1 of 2)
    The linework for all the quadrangles was originally digitized by Jeff Wynn with GSMAP (Selner and Taylor, 1987), a USGS-authored map editing and publishing program. Conversion from GSMAP to ARC/INFO was accomplished with GSMARC (Green and Selner, 1988). The three northern quadrangles were later re-scanned on an Tektronix 4991 autovectorizing drum scanner by Paul Schruben from the geologists' revised drawings. The arcs and polygons were tagged in ARC/INFO and the oriented point symbols such as bedding and joint symbols were created with Alacarte (Wentworth and Fitzgibbon, 1991).
    Date: 08-Jun-2009 (process 2 of 2)
    Creation of original metadata record Person who carried out this activity:
    Jennifer Lenz
    Mail Stop 918 National Center
    U.S. Geological Survey
    12201 Sunrise Valley Drive
    Reston, VA
    USA

    (703) 648-6974 (voice)
    (703) 648 6533 (FAX)
    pschweitzer@usgs.gov
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    The geologic map is primarily a bedrock map, which depicts geologic materials present beneath the soil or relatively thin mantles of surficial deposits, not necessarily the surficial materials themselves. Indeed, the study area contains so much surficial cover and standing water that much of the mapping was accomplished with geophysical methods as opposed to directly examining rock outcrops.
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    The "quadrangle" maps in this publication cover somewhat more or less than 2øx3ø depending on the specific map. For instance, the Guri map (Cox and others, 1993) contains all of the Guri quadrangle and the southern part of the Tucupita quadrangle. The entire study area in the southeast part of Venezuela, known as the Venezuelan Guayana Shield, is about 36 inches tall at 1:1 million scale, which is the published scale for Bulletin 2062 (USGS and Corporaci¢n Venezolana de Guayana, T‚cnica Minera, C.A., 1993).
  5. How consistent are the relationships among the observations, including topology?
    The coverages for the individual quadrangles have the same features as the combined coverage. The only differences are in some of the file names. For instance, the place names and city points in the individual quadrangles are stored in files called "*anno5.e00" as opposed to "places.e00" for the combined coverage.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: none
Use_Constraints: none
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey, Map Distribution
    Box 25286, Denver Federal Center
    Denver, CO
    USA

    1-888-ASK-USGS (voice)
    (303) 202-4693 (FAX)
  2. What's the catalog number I need to order this data set? US Geological Survey Digital Data Series 46
  3. What legal disclaimers am I supposed to read?
    This Compact Disc-Read Only Memory (CD-ROM) publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
    Although all data and software published on this CD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the U.S. Geological Survey as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data, software, or related materials.
    Graphical map depictions on this disc are intended to be used within the map scale limits applicable to the source data. Although software enables the user to show images on the disc at various scales, the user is cautioned to refer to the source documentation for the appropriate map scale limitations.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 10-Jun-2016
Metadata author:
Peter N Schweitzer
USGS Midwest Area
Collection manager, USGS Geoscience Data Clearinghouse, http://geo-nsdi.er.usgs.gov/
Mail Stop 954
12201 Sunrise Valley Dr
Reston, VA
USA

703-648-6533 (voice)
703-648-6252 (FAX)
pschweitzer@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://geo-nsdi.er.usgs.gov/metadata/digital-data/46/metadata.faq.html>

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: https://geo-nsdi.er.usgs.gov/metadata/digital-data/46/metadata.faq.html
Page Contact Information: Peter Schweitzer
Page Last Modified: Monday, 14-Aug-2017 12:00:54 EDT

Generated by mp version 2.9.40 on Mon Aug 14 12:00:54 2017